Magnetic interactions in equi-atomic rare-earth intermetallic alloys RScGe (R = Ce, Pr, Nd and Gd) studied by time differential perturbed angular correlation spectroscopy andab initiocalculations

2009 ◽  
Vol 21 (11) ◽  
pp. 115601 ◽  
Author(s):  
S N Mishra
Keyword(s):  
Rare Earth ◽  
Angular Correlation ◽  
Perturbed Angular Correlation ◽  
Correlation Spectroscopy ◽  
Magnetic Interactions ◽  
Intermetallic Alloys ◽  
Perturbed Angular Correlation Spectroscopy ◽  
Time Differential ◽  
Rare Earth Intermetallic

scholarly journals 181Ta (← 181Hf) Time-Differential Perturbed Angular Correlation Spectroscopy of Hf/Fe Multilayers

2004 ◽  
Vol 45 (7) ◽  
pp. 2008-2011
Author(s):  
Takashi Ohtomo ◽  
Saburo Nasu ◽  
Masahiro Miyasaka ◽  
Shotaro Morimoto ◽  
Koji Baba ◽  
...  
Keyword(s):  
Angular Correlation ◽  
Perturbed Angular Correlation ◽  
Correlation Spectroscopy ◽  
Perturbed Angular Correlation Spectroscopy ◽  
Time Differential

scholarly journals Chemical Transformation of Crystalline Hafnium Tetrafluoride Studied by Perturbed Angular Correlation Spectroscopy

2009 ◽  
Vol 64 (11) ◽  
pp. 739-744 ◽  
Author(s):  
Chandi Charan C. Dey
Keyword(s):  
Angular Correlation ◽  
Chemical Transformation ◽  
Perturbed Angular Correlation ◽  
Correlation Spectroscopy ◽  
Correlation Technique ◽  
Perturbed Angular Correlation Spectroscopy ◽  
Time Differential ◽  
Coincidence Set ◽  
Set Up ◽  
Hafnium Tetrafluoride

The chemical transformation of the trihydrate hafnium tetrafluoride crystal has been studied with varying temperature using the time-differential perturbed angular correlation technique. The 133 - 482 keV γ -γ cascade of 181Ta after the β −-decay of 181Hf has been selected and a four detector BaF2-BaF2 coincidence set up has been used for measurements. The crystal was produced by evaporating a solution of HfF62−complex in HF at room temperature. Contrary to the earlier report, it has been found that the trihydrate hafnium tetrafluoride compound dehydrates directly to HfF4 without producing any intermediate monohydrate and present results do not support the earlier idea that two water molecules of HfF4·3H2O are loosely bound. Present investigations exhibit a superheated state for the hafnium tetrafluoride crystal. In dehydrated HfF4, two different Hf sites have been observed which suggests two different structures for the anhydrous HfF4.

Defects in CdS: In detected by perturbed angular correlation spectroscopy (PAC)

1991 ◽  
Vol 50 (1-4) ◽  
pp. 159-164 ◽  
Author(s):  
R. Magerle ◽  
M. Deicher ◽  
U. Desnica ◽  
R. Keller ◽  
W. Pfeiffer ◽  
...  
Keyword(s):  
Angular Correlation ◽  
Perturbed Angular Correlation ◽  
Correlation Spectroscopy ◽  
Perturbed Angular Correlation Spectroscopy

scholarly journals Comparison of Jump Frequencies of 111In/Cd Tracer Atoms in Sn3R and In3R Phases Having the L12 Structure (R = Rare-Earth)

2011 ◽  
Vol 311 ◽  
pp. 159-166 ◽  
Author(s):  
Megan Lockwood Harberts ◽  
Benjamin Norman ◽  
Randal Newhouse ◽  
Gary S. Collins
Keyword(s):  
Rare Earth ◽  
Perturbed Angular Correlation ◽  
Diffusion Mechanism ◽  
Correlation Spectroscopy ◽  
Perturbed Angular Correlation Spectroscopy ◽  
Dominant Mechanism ◽  
Boundary Composition ◽  
Light Lanthanide ◽  
Diffusion Mechanisms ◽  
Jump Frequencies

Measurements were made of jump frequencies of 111In/Cd tracer atoms on the Sn-sublattice in rare-earth tri-stannides having the L12 crystal structure via perturbed angular correlation spectroscopy (PAC). Phases studied were Sn3R (R= La, Ce, Pr, Nd, Sm and Gd). Earlier measurements on isostructural rare-earth tri-indides showed that the dominant diffusion mechanism changed along that series [4]. The dominant mechanism was determined by comparing jump frequencies measured at opposing phase boundary compositions (that is, more In-rich and more In-poor). Jump frequencies were observed to be greater at the In-rich boundary composition in light lanthanide indides and greater at the In-poor boundary composition in heavy-lanthanide indides. These observations were attributed to predominance of diffusion via rare-earth vacancies in the former case and indium vacancies in the latter. Contrary to results for the indides, jump frequencies found in the present work are greater for the Sn-poor boundary compositions of the stannides, signaling that diffusive jumps are controlled by Sn-vacancies. Possible origins of these differences in diffusion mechanisms are discussed.

scholarly journals Perturbed Angular Correlation Studies in SrTiO3 Single Crystals

2000 ◽  
Vol 55 (1-2) ◽  
pp. 237-241
Author(s):  
P. de la Presa ◽  
K. P. Lieb ◽  
M. Uhrmacher ◽  
L. Ziegeler
Keyword(s):  
Angular Correlation ◽  
Perturbed Angular Correlation ◽  
Hyperfine Interactions ◽  
Correlation Spectroscopy ◽  
Quadrupole Frequency ◽  
Perturbed Angular Correlation Spectroscopy ◽  
Temperature Range ◽  
Field Gradients ◽  
Electronic Defects ◽  
Asymmetry Parameters

The quadrupole hyperfine interactions of 111Cd/111 In probe nuclei in single-crystalline SrTiO3 perovskite samples were investigated using Perturbed Angular Correlation spectroscopy. Three electric field gradients were detected and their fractions and hyperfine parameters were measured in the temperature range from 26 to 700 K. The fraction f0 having a vanishing quadrupole frequency, as expected for 111Cd on substitutional sites in a cubic lattice, starts to develop around 300 K and reaches 100% at 700 K. Two well-defined EFG's having closely lying quadrupole frequencies and asymmetry parameters of ωQi = 49.1(3) Mrad/s, 77, η0= 0.10(2) and ωQ2 = 51.8(3) Mrad/s, η2 = 0.12(2), at room temperature, were identified in the temperature range from 250 to 530 K, and their (100) orientation in the lattice was determined. They are associated with electronic defects at the probe atoms.

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